C语言qsort函数用冒泡排序实现过程详解

void bubble_sort(int arr[], int sz)
{
	//趟数
	int i = 0;
	for (i = 0; i < sz - 1; i++)
	{
		//一趟冒泡排序的过程
		int j = 0;
		for (j = 0; j < sz - 1 - i; j++)
		{
			if (arr[j] > arr[j + 1])
			{
				int tmp = arr[j];
				arr[j] = arr[j + 1];
				arr[j + 1] = tmp;
            }
		}
	}
}

//用qsort函数实现各种类型的排序
//整形数组的排序
int cmp_int(void const* e1, void const* e2)
{
	return *(int*)e1 - *(int*)e2;
}
int main()
{
	int i = 0;
	int arr[10] = { 9,8,7,6,5,4,3,2,1,0 };
	int sz = sizeof(arr) / sizeof(arr[0]);
	qsort(arr, sz, 4, cmp_int);
	for (i = 0; i < 10; i++)
	{
		printf("%d ", arr[i]);
	}
	return 0;
}
//结构体的排序
struct stu
{
	char name[20];
	int  age;
};
int cmp_age(void const*e1, void const*e2)
{
	return (((struct stu*)e1)->age - ((struct stu*)e2)->age);
}
int cmp_name(void const* e1, void const* e2)
{
	return strcmp(((struct stu*)e1)->name ,((struct stu*)e2)->name);
}
int main()
{
	struct stu Stu[3] = { {"zhangsan", 20},{"wangwu", 42},{"lisi",29}};
	int sz = sizeof(Stu) / sizeof(Stu[0]);
	//qsort(Stu, sz, sizeof(Stu[0]), cmp_age);
	qsort(Stu, sz, sizeof(Stu[0]), cmp_name);
	return 0;
}

//实现元素的交换
void swap(char* e1, char* e2, size_t sz)
{
	size_t i = 0;
	for (i = 0; i < sz; i++)
	{
		char tmp = 0;
		tmp = *e1;
		*e1 = *e2;
		*e2 = tmp;
		e1++;
		e2++;
	}
}
//qsort函数的自定义
void bubble_sort(void* base, size_t num, size_t size, int (*compar)(const void*e1, const void*e2))
{
	size_t i = 0;
	size_t j = 0;
	//冒泡排序的趟数
	for (i = 0; i < num-1; i++)
		{
			//比较的次数
			for (j = 0; j < num - i - 1; j++)
			{
				if (compar((char *)base+j*size,(char*)base+(j+1)*size)>0)
				{
					//交换
					swap((char*)base + j*size, (char*)base + (j + 1)*size, size);
				}
			}
		}
}